The present invention relates to a method of producing chlorinated polyolefin in aqueous medium system suitable for the film-forming uses such as paint, ink, adhesive, etc.
The chlorinated product of polyolefin by production method in aqueous medium has a feature originating from inhomogeneity of chlorination over that obtainable by chlorinating method in solution system and does not require the removing solvents technique and the measures for preventing environmental contamination brought by solvent. Hence, it is used for molded articles and modifier of resins.
The production methods of chlorinated polyolefin in aqueous medium having been proposed so far are for the uses for molding materials and improvement materials of physical properties of resins. The chlorine content is as low as 15 to 50 wt. % (Japanese Unexamined Patent Publication No. Sho 51-138791) and the nonuniform of chlorination is also utilized as a feature of chlorinating method in aqueous medium (for example, Japanese Unexamined Patent Publication No. Sho 54-153831, No. Sho 59-68354, etc.).
However, with conventional chlorinated polyolefins in aqueous suspension system, it is impossible to prepare homogeneous solutions of inexpensive solvents (for example, toluene and xylene) ordinarily used. Although a method for obtaining homogeneous solvent solution by dissolving under at elevated temperatures (Japanese Unexamined Patent Publication No. Sho 54-153853) is proposed, it is not a method enough satisfied.